The way I see it is that was in a covenant with God where by obedience to His command, Adam would live, but by disobedience he would die. It was the result of disobedience to this that Adam committed and act of unrighteousness (1 John 3:4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law) and have a fallen nature (Jeremiah 17:9 The heart is deceitful above all things, and desperately wicked: who can know it?) and must die (Ezekiel 18:20 The soul that sinneth, it shall die).
So Christ, as the second Adam, must undo what was done, and solve each of the 3 problems that resulted from the violation of God's Covenant (which was created and began to be at some point in time). If sin is transgression of the law, notice the comparison here (2 Corinthians 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him) in the same way that he was made sin, we are made righteous. And if sin is transgression of the law, the righteousness as used here, is always doing what is right. Note that before we could be made righteous, he needed to be made sin, so whatever our disagreements may be on the nature of the righteousness, the death and sin first needed to be taken cared of. This transfer here is by imputation and substitution as we see in in Isaiah 53:6 "We all, like sheep, have gone astray, each of us has turned to our own way; and the LORD has laid on him the iniquity of us all." The idea the of the transfer if guilt is not foreign to the scriptures, and is basically the idea behind all propitious sacrifice, and is clearly depicted in the Old Testament by the laying of hands on the guilt offering, transferring guilt to it.
The necessity of the death and the life are shown in this passage:
(Romans 5 9Much more then, being now justified by his blood, we shall be saved from wrath through him. 10For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life. 11And not only so, but we also joy in God through our Lord Jesus Christ, by whom we have now received the atonement.)
Atonement then is both the removal of wrath but also in a real sense salvation by His works (note that in the Levitical sacrifice, the lamb had to be pure).
But that leaves the transformation and Glorification of the fallen human, into the image of Christ. The believer is united to Christ and upon regeneration is made a new creature, by the same divine power of the Ressurection. It's the Ressurection life that the believer has. And this life is Divine in origin as scripture says 1 Peter 1:23 "for you have been born again not of seed which is perishable but imperishable, that is, through the living and enduring word of God." And Christ being the Word of God and eternal life manifested in the flesh, it is in His life that we partake John 6:57 "Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me."
The death and active obedience though the result of a covenant that was created and violated, are eternally significant. They remove the obstacles necessary so that the transformation of fallen man, into a new righteous nature may take place. But the righteousness of Christ human obedience, just by virtue of being human because it results from fulfilling a covenant that humans were under, is not something small. For it's by this that we read Phillipians 2:7-8 "but emptied himself, by taking the form of a servant, being born in the likeness of men. 8 And being found in human form, he humbled himself by becoming **obedient** to the point of death, even death on a cross. 9 **Therefore** God has highly exalted him and bestowed on him the name that is above every name."
Christ's eternal exaltation by resurrection, ascension and enthronement, are by virtue of this "human righteousness" so to speak. His Divine righteousness, being under no covenant or authority, is simply who he is as God. His human righteousness is both passive, by virtue of a sinless human nature and an active one, by virtue of his obedience.
So all that say, I'm not sure if I've answered the question on the relation between us and His divine nature, but as I said, a person does not exist apart from a nature, so His Divine is still crucial to all this, I just can't exact point to how (I've not really thought much on these things, I've only recently got sort of a grasp on the nature of the active obedience). Maybe Hebrews 9:14 can shed light, I'm not sure "How much more, then, will the blood of Christ, who through the **eternal Spirit** offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!"
Either way, I don't see an issue, and this is why the difference between sanctification and justification are crucial to understand in Protestant thinking. They are of course related but there is a distinction.
That's my take on it anyways
